Turkish Journal of Chemistry, Vol.26, No.1, 17-22, 2002
Determination of trace amounts of gold(III) using ethopropazine hydrochloride and isothipendyl hydrochloride: A spectrophotometric study
Two simple, sensitive and accurate spectrophotometric methods have been proposed for the determination of micro amounts of gold (III) using ethopropazine hydrochloride (EPH) and isothipendyl hydrochloride (IPH). The methods arc based on the oxidation of phenothiazines by gold (III) to give red radical cations having maximum absorption at 513 and at 512 nm with molar absorptivities of 2.0 X 10(4) and 2.1 X 10(4)l mol(-1) cm(-1) for EPH and IPH respectively. Beer's law is valid over the concentration range 0.5-14.1 mg l(-1) for EPH and 0.5-14.5 mg l(-1) for IPH. The proposed methods have been successfully applied for the determination of gold (III) in synthetic mixtures.